Single tubing string dual installation



Apnl 2, 1963 J. B. CHAPMAN SINGLE TUBING STRING DUAL INSTALLATION Filed May 18, 1959 SAFETY FLOW FIG.

FIG. 2.

VALVE IN V EN TOR.

BLAN K'OFF SAFETY FLOW VALVE j 32 .i l iii i ii: ii-555.55:

JOHN B. CHAPMAN,

ATTORNEY.

United States Patent This invention is directed primarily to an installation for producing upper and lower hydrocarbon productive intervals. More particularly, the invention is concerned with single tubing string dual completions wherein safety M valves may be required for controlling both the upper and lower interval production fluids.

it is known to equip wells with subsurface safety valves to stop the flow of production fluids when for some reason the wells production cannot be controlled. Valves of this type have been especially useful in offshore wells to prevent blowouts when excessive flow from the well resulting from damage to the well head or other surface equipment caused by storms, floating objects, or other happenings necessitate halting of production.

These valves may be flow velocity operated; that is, they may be designed to close off production flow when the velocity of the fluids flowing through the valve reaches a predetermined value. However, other type valves may be employed. The type completion to which the invention refers and of which two embodiments are illustrated is that wherein two spaced-apart productive intervals are completed utilizing a single tubing string extending to the earths surface. Separate flow paths are provided for the upper and lower intervals, one of the flow paths being through the tubing-casing annulus and the other flow path being through the single tubing string.

Either of the installations shown may be equipped with permanent type completion apparatus for working over the lower or the upper interval as the case may be.

A full discussion of permanent well completion opertions may be found in Permanent Type Completions and Wire Line Workovers, The Petroleum Engineer, September 1956.

In one embodiment of the invention, the upper zone or interval is produced through a perforated nipple and the single tubing string and the lower zone is produced through a pipe section and the tubing casing annulus. In another embodiment, the upper zone is produced through a perforated nipple and the tubing casing annulus and the lower zone is produced through a pipe section and the tubing string. Thus, the producing flow paths are reversed in each of the embodiments. Safety valves are provided for each flow path.

An object of this invention is to provide improved apparatus for producing a plurality of hydrocarbon productive intervals of a dually completed well while providing the separate flow paths with safety valves.

This and other objects of the invention will be apparent from the following description thereof taken in conjunction with the drawings wherein:

FIG. 1 is a cross-sectional view of a well bore having therein dual completion apparatus arranged according to one embodiment of the invention; and

FIG. 2 is a view similar to that of FIG. 1 showing the dual completion apparatus arranged in the well bore according to another embodiment of the invention.

Referring more particularly to the drawings wherein identical numerals designate identical parts:

A casing 10 is shown in FIGS. 1 and 2 arranged in a borehole 11. Cased borehole 11 penetrates spaced-apart hydrocarbon productive zones or intervals 12 and 13. Casing 10 and intervals 12 and 13 are perforated as at 14 and 15, respectively.

3 ,983,771 Patented Apr. 2, 1963 A lower casing production packer 16 provided with a bore 17 therethrough is positioned between upper and lower zones 12 and 13, respectively.

An upper casing production packer 18 provided with dual bores 19 and 20 is positioned above upper zone 12.

In FIG. 1, a tubing string 21, which may be provided with a gas-lift mandrel 22, extends from the earths surface, not shown, through bore 19 of packer 18. Tubing string 21 below mandrel 22 is provided with an upper landing nipple 24, a perforated section 25, and a lower landing nipple 26. Above mandrel 22, tubing string 21 is provided with a landing nipple 23. An openended pipe string 27 is connected to pipe string 21 adjacent mandrel 22 at its upper end and extends through bore 20 of packer 18 and through bore 17' of packer 16.

In a desired mode of operation, packer 16 is initially run on a wire line and set between zones 12 and 13. Pipe strings 21 and 27 are connected together, and packer 18 is arranged thereon. The two pipe strings are then run together until pipe string 27 stabs through bore 17 of packer 16. A guide member 28 may be provided on packer 16 to facilitate stabbing of pipe string 27 through bore 17. Also, pipe string 27 is provided with a pack-off 29 to seal off the space between the wall of bore 17 and pipe string 27. Straps 30 may be employed to strap pipe strings 21 and 27 together to aid in the running-in operation. A suitable plug choke or blankoff 31, a safety flow valve 33 and a safety flow valve 32 are run on wire lines and arranged respectively in landing nipples 24, 23 and 26. Safety valve 33 could be located in mandrel 22 instead of in landing nipple 23 if desired.

In the operation of the embodiment of FIG. 1, the how path for production fluids from zone 13 is up pipe string 27 into pipe string 21 abov the plug 31 and thence upwardly through tubing string 21 and through safety valve 33. Flow of production fluids from upper zone 12 is upwardly through the lower end of tubing string 21, through safety valve 32, through the openings or perforations in the perforated section 25 and thence upwardly to the surface of the earth through the tubing-casing annulus A. Thus, although one flow path is through the tubing-casing annulus, both flow paths are provided with safety valves.

In FIG. 2, the flow paths are reversed. A tubing string 35 extends from the earths surface through bore 19 of packer 18 and through bore 17 of packer 16. Again, a pack-off 29 is employed to close off the space between tubing string 35 and the wall of bore 17 and guide means 28 may be provided to facilitate stabbing pipe string 35 through bore 17. Tubing string 35 is also provided with a landing nipple 34 above packer 18, a perforated nipple 36 below packer 18, another landing nipple 37 below perforated nipple 36, and a third landing nipple 38 positioned below landing nipple 37. A pipe string 39 connects to pipe string 35 between landing nipples 37 and 38 and extends upwardly through bore 20 of packer 18. A safety valve 40, a plug choke or blanking plug 41 and another safety flow valve 42 are run on wire lines and arranged, respectively, in landing nipples 34, 3'7 and 38.

Production fluids from the lower zone in this embodiment flow through perforations 15 upwardly through the lower portion of tubing string 35, through safety flow valve 42, through pipe string 39, and upwardly through annulus A between tubing string 35 and casing 10. Flow of production fluids from the upper Zone 12 is through perforations 14, through perforations in the perforated nipple 36 upwardly through safety valve 40 and through the upper portion of the tubing string 35 to the earths surface. Thus, in this embodiment, also both flow paths are provided with safety valves although one of the flow paths is substantiallythrough'the tubing-casing annulus.

The equipment described in this application is wellknown in the art as, for example, the safety valves,

blanking plugs, and duallbore and single bore packers; therefore, neither a detailed description of this equipment nor specific reference to any particular equipment has been made.

Having fully described the nature, objects, and apparatus of rny invention, I claim:

Apparatus for producing hydrocarbons from upper and lower spaced-apart subsurface hydrocarbon productive intervals penetratedby a 'well'bore to the earths surface through isolated flow paths comprising one pipe string arranged in said boreholeand extending from the earths surface to abovean'd adjacent said upper productive interval; another pipe string connected to said one pipe string along the length 1 thereof, offset therefrom, and extending to below said upper productive interval; an

'upper dual-bore packer arrangedon said pipe strings 'abov'esa'i'd upper productive intervatclosingoff the space between said *pipe :strings and the well bore wall; a lower'single bo're packer arrz'tngecl on said other pipe string between said upper and lower productive intervals closingoff the space between said other pipe string and/the well bore wall; saidone pipe string having 'perforationsbelow the interconnection between said pipe strings "'fluidlycommunicatingthe interior of said one pipe string and'the space surrounding said pipe'strings;

a plug arranged in said one pipe string above said perforations in said one pipe string but below the connection between said pipe strings for preventing fluid flow upwardly therepast and to direct fluid flow through the pipe strings to establish isolated flow paths for hydrocarbon fluids flowing from each of said productive inter- "fluids from said upper productive interval flow through said one safety valve and said perforations and the space between said one pipe string and the borehole wall to the earths surface and fluids from said lower production interval flow upwardly through said other pipe string, said other safety valve, and said one pipe string to the earths surface.

References Cited in the file of this patent UNITED STATES PATENTS 2,433,942 Works Jan. 6, 1948 2,822,048 Tausch Feb. 4, 1948 2,870,843 Rodgers Jan. 27, 1959 2,935,131 McCune May 3, 1960 

